1. Field of the Invention
The present invention relates to a method of manufacturing an organic electroluminescence display device (organic EL display device) comprising an electroluminescence layer (organic EL layer) for emitting a light by the application of a current.
2. Description of the Related Art
In the organic electroluminescence display device of this type, generally, a large number of stripe-shaped anode electrodes 12 formed by a transparent conductive film are arranged in parallel at a proper interval on a back face 11b opposite to a surface 11a in a transparent substrate 11 such as a glass, an electroluminescence layer 13 is overlaid on each of the stripe-shaped anode electrodes 12, a large number of stripe-shaped cathode electrodes 14 formed by a metal layer are arranged on the electroluminescence layer 13 in parallel at a proper interval in such a direction as to cross the stripe-shaped anode electrode 12, and a current is applied between any of the stripe-shaped anode electrodes 12 and any of the stripe-shaped cathode electrodes 14 to emit a light to the electroluminescence layer 13 in a portion provided therebetween so that a character is displayed on the surface 11a side in the transparent substrate 11 as shown in FIGS. 1 to 3.
A cover 15 for wholly covering the stripe-shaped anode electrode 12, the electroluminescence layer 13 and the stripe-shaped cathode electrode 14 is attached to the back face 11b in the transparent substrate 11.
When an organic electroluminescence display device having this structure is to be manufactured, conventionally, there is employed a first method in which “the large number of stripe-shaped anode electrodes 12 are first formed on the back face 11b of the transparent substrate 11, the organic electroluminescence layer 13 is then overlaid thereon, and a metal mask comprising a through hole according to the pattern of the large number of stripe-shaped cathode electrodes 14 formed by the metal layer is overlaid on the surface of the organic electroluminescence layer 13, and the stripe-shaped cathode electrodes 14 are formed by the metal layer through vacuum evaporation of metal from thereabove, or
a second method in which “the large number of stripe-shaped anode electrodes 12 are formed on the back face 11b of the transparent substrate 11, a cathode partition layer is then overlaid thereon by a photoresist and is subjected to patterning according to the stripe-shaped cathode electrodes 14 by photolithography using pattern exposure and baking and a development processing, and the organic electroluminescence layer 13 is formed between the cathode partition layers and the stripe-shaped cathode electrode 14 is thereafter formed on the surface of the cathode partition layer.”
In these manufacturing methods, however, there is a problem in that the steps of forming the stripe-shaped cathode electrode 14 is remarkably increased and complicated, resulting in a considerable increase in a manufacturing cost.
In addition, as in the former case, the method of forming the stripe-shaped cathode electrode 14 by vacuum evaporation using a metal mask has a problem in that the dimension and shape of each of the stripe-shaped cathode electrodes 14 depends on that of the through hole in the metal mask, resulting in a reduction in precision in the dimension and shape and the difficulty of an increase in fineness. In the method of forming the stripe-shaped cathode electrode 14 as in the latter case, moreover, there is a problem in that an increase in fineness is limited and the alignment of a pattern is hard to perform.